Upas

Upas, from the Javanese word for "poison", refers to an evergreen tree known as Antiaris toxicaria. A native of southeastern Asia with highly poisonous sap. it is the source of the following literary allusions.

‘When you first came upon me, sir, in the Lodge, this day, more as if an Upas tree had been made a capture of than a private defendant, such mingled streams of feelings broke loose again within me, that everything was for the first few minutes swept away before them, and I was going round and round in a vortex...'

Farther on, there frowned a grove of blended banian boughs, thick-ranked manchineels, and many a upas; their summits gilded by the sun; but below, deep shadows, darkening night-shade ferns, and mandrakes.

"What's the tree I read about somewhere that does you in if you sit under it?", to which Jeeves replies, "The upas tree, sir." Bertie rejoins, "She's a female upas tree. It's not safe to come near her."